/*
* Copyright (C) 2011 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.base;
import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.collect.ImmutableSet;
import com.google.common.testing.GcFinalization;
import com.google.common.testing.NullPointerTester;
import com.google.common.testing.SerializableTester;
import junit.framework.TestCase;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.ref.WeakReference;
import java.lang.reflect.Field;
import java.net.URLClassLoader;
import java.util.HashSet;
import java.util.Set;
/**
* Tests for {@link Enums}.
*
* @author Steve McKay
*/
@GwtCompatible(emulated = true)
public class EnumsTest extends TestCase {
private enum TestEnum {
CHEETO,
HONDA,
POODLE,
}
private enum OtherEnum {}
public void testGetIfPresent() {
assertEquals(Optional.of(TestEnum.CHEETO), Enums.getIfPresent(TestEnum.class, "CHEETO"));
assertEquals(Optional.of(TestEnum.HONDA), Enums.getIfPresent(TestEnum.class, "HONDA"));
assertEquals(Optional.of(TestEnum.POODLE), Enums.getIfPresent(TestEnum.class, "POODLE"));
assertTrue(Enums.getIfPresent(TestEnum.class, "CHEETO").isPresent());
assertTrue(Enums.getIfPresent(TestEnum.class, "HONDA").isPresent());
assertTrue(Enums.getIfPresent(TestEnum.class, "POODLE").isPresent());
assertEquals(TestEnum.CHEETO, Enums.getIfPresent(TestEnum.class, "CHEETO").get());
assertEquals(TestEnum.HONDA, Enums.getIfPresent(TestEnum.class, "HONDA").get());
assertEquals(TestEnum.POODLE, Enums.getIfPresent(TestEnum.class, "POODLE").get());
}
public void testGetIfPresent_caseSensitive() {
assertFalse(Enums.getIfPresent(TestEnum.class, "cHEETO").isPresent());
assertFalse(Enums.getIfPresent(TestEnum.class, "Honda").isPresent());
assertFalse(Enums.getIfPresent(TestEnum.class, "poodlE").isPresent());
}
public void testGetIfPresent_whenNoMatchingConstant() {
assertEquals(Optional.absent(), Enums.getIfPresent(TestEnum.class, "WOMBAT"));
}
@GwtIncompatible("weak references")
public void testGetIfPresent_doesNotPreventClassUnloading() throws Exception {
WeakReference<?> shadowLoaderReference = doTestClassUnloading();
GcFinalization.awaitClear(shadowLoaderReference);
}
// Create a second ClassLoader and use it to get a second version of the TestEnum class.
// Run Enums.getIfPresent on that other TestEnum and then return a WeakReference containing the
// new ClassLoader. If Enums.getIfPresent does caching that prevents the shadow TestEnum
// (and therefore its ClassLoader) from being unloaded, then this WeakReference will never be
// cleared.
@GwtIncompatible("weak references")
private WeakReference<?> doTestClassUnloading() throws Exception {
URLClassLoader myLoader = (URLClassLoader) getClass().getClassLoader();
URLClassLoader shadowLoader = new URLClassLoader(myLoader.getURLs(), null);
@SuppressWarnings("unchecked")
Class<TestEnum> shadowTestEnum =
(Class<TestEnum>) Class.forName(TestEnum.class.getName(), false, shadowLoader);
assertNotSame(shadowTestEnum, TestEnum.class);
Set<TestEnum> shadowConstants = new HashSet<TestEnum>();
for (TestEnum constant : TestEnum.values()) {
Optional<TestEnum> result = Enums.getIfPresent(shadowTestEnum, constant.name());
assertTrue(result.isPresent());
shadowConstants.add(result.get());
}
assertEquals(ImmutableSet.copyOf(shadowTestEnum.getEnumConstants()), shadowConstants);
Optional<TestEnum> result = Enums.getIfPresent(shadowTestEnum, "blibby");
assertFalse(result.isPresent());
return new WeakReference<ClassLoader>(shadowLoader);
}
public void testStringConverter_convert() {
Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
assertEquals(TestEnum.CHEETO, converter.convert("CHEETO"));
assertEquals(TestEnum.HONDA, converter.convert("HONDA"));
assertEquals(TestEnum.POODLE, converter.convert("POODLE"));
assertNull(converter.convert(null));
assertNull(converter.reverse().convert(null));
}
public void testStringConverter_convertError() {
Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
try {
converter.convert("xxx");
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testStringConverter_reverse() {
Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
assertEquals("CHEETO", converter.reverse().convert(TestEnum.CHEETO));
assertEquals("HONDA", converter.reverse().convert(TestEnum.HONDA));
assertEquals("POODLE", converter.reverse().convert(TestEnum.POODLE));
}
@GwtIncompatible("NullPointerTester")
public void testStringConverter_nullPointerTester() throws Exception {
Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
NullPointerTester tester = new NullPointerTester();
tester.testAllPublicInstanceMethods(converter);
}
public void testStringConverter_nullConversions() {
Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
assertNull(converter.convert(null));
assertNull(converter.reverse().convert(null));
}
@GwtIncompatible("Class.getName()")
public void testStringConverter_toString() {
assertEquals(
"Enums.stringConverter(com.google.common.base.EnumsTest$TestEnum.class)",
Enums.stringConverter(TestEnum.class).toString());
}
public void testStringConverter_serialization() {
SerializableTester.reserializeAndAssert(Enums.stringConverter(TestEnum.class));
}
@GwtIncompatible("NullPointerTester")
public void testNullPointerExceptions() {
NullPointerTester tester = new NullPointerTester();
tester.testAllPublicStaticMethods(Enums.class);
}
@Retention(RetentionPolicy.RUNTIME)
private @interface ExampleAnnotation {}
private enum AnEnum {
@ExampleAnnotation FOO,
BAR
}
@GwtIncompatible("reflection")
public void testGetField() {
Field foo = Enums.getField(AnEnum.FOO);
assertEquals("FOO", foo.getName());
assertTrue(foo.isAnnotationPresent(ExampleAnnotation.class));
Field bar = Enums.getField(AnEnum.BAR);
assertEquals("BAR", bar.getName());
assertFalse(bar.isAnnotationPresent(ExampleAnnotation.class));
}
}